Method of conducting combustion.



H. L. DOHERTY.

Patented July 6, 1915.

2 SHEETS-SHEET 1- METHOD 0F CONDUCTING COMBUSTION.

APPLICATION FILED IAN. 17. 19H. 1,145,357.

H. L.noHERTY'. METHOD 0F CONDUCTING CDMBUSWW'N. APPLICATION FILED IAN.17, |911.

1,145,357. Pmnquly 6, 1915.

2 SHEETS-SHEET 2. m FIGB.

Henry L Dollaerty, Syn/vento@ HENRY L. DOHERTY, OF'NEW YORK, N. Y.

METHOD 0F CONDUCTING C OMBUSATION.

Specification of Letters Patent.

Patented July 6, 1915.

Application mea January rz, 1911. serial No. 603,088.

To all whom t may concern Be it known that I, HENRY L. DOHERTY, acitizen of the United States, and a resident of New York city, in thecounty of New York and State of New York, have invented certain new anduseful Improvements in .Methods of Conducting Combustion, of

which the following is a specification.

My invention relates to a method of conducting combustion, and, inparticular, to a method of conducting combustion v1n the heating fiuesof a coke-oven. a

The object of my invention is to provide a method of conductingcombustion in a coke oven or other furnace whereby a uniform heatingeect is secured from the top to the bottom of the oven and the maximumeconomy of combustion obtained.

My method consists in securing a prolonged combustion in theheatingiiues by burning a portion of the heating gas in the top lues with anexcess of air and then adding to the stream of combustion products fromthe upper combustion iiue, alternately, an excess of gas and an excessof air, the proportion of the gas burned in the other iiues being soregulated that a fairly uniform temperature is established in all thecombustion flues, both the air and gasused in the combustion beingheated in separate recuperators by the hot products of combustiondischarging from the heating flues.

In the accompanying drawings, I have shown a form of apparatus forapplying my invention.

Figure 1 is a longitudinal section through one set of heating filles andone set of recuperator lues and the gas producer on the line F, F1, F11,F111, F11', FV, F111, F1111 of Fig.

2. Fi 2 is a vertical cross-section of one half o the apparatus on theline A, A1, A11, A111, A12-'AV of Fig. 1. Fig. 3 is a vertical crosssection of the other half of the apparatus on the line B, B1, B11, B111of Fig. 1. Fig. 4 is asimilar section of one half of the apparatus onthe line C, C1, C11, C111, C111, CV, CVI, C111 of Fig. 1. Fig. 5 is asimilar section of the other half on the line DD of Fig. 1. Fig. 6 is a'horizontal cross-sec tion on'the line EE of Fig. 1.

1 is thecoking chamber or ovenl proper of the oven setting; 2 the gasproducer; 3 the air recuperator; 4 the gas recuperator. 5 is the maincombustion gas flue conducting away the flue gases from a battery ofovens.

61, 611, 6111, 61V, etc., are the heating or combustion iues of the ovenon one side and 71 711, 7111, 71V, etc., are the combustion iiues of theother side of the oven.

8 and 8 are the gas up-take lues for the two sides of the oven and 9 and9 the air up-take flues.

101, 10111, 10V, etc., are the gas nostrils connecting the gas flue 8with the combustion ues 61, 6111 and 6V.

111-1, 111v and 11v1 are the air nostrils connecting the air l'ue 9 withthe combustion flues 611, 61V and 6111.

121, 12111, 12V are the gas nostrils connecting the gas fiue 8 with thecombustion iiues 71, 7111 and7v.

1311, 131V and 13111 are the corresponding air nostrils or ports for theside of the oven in which are located the combustion lues 71 to 7V11.

Dampers 14 and 14. provide a means for regulating the flow of gasthrough the gas nostrils, and dampers 15 and 15 a means for regulatingthe iiow of air through the air nostrils.

-The oven is symmetrical in all respects in relation to a vertical planethrough its middle, so that thereproduction of both sides of the oven inthe several views is unnecessary to a clear showing of its construction,but numerals referring to the duplicate parts are introduced herein, forthesake of brevity and clearness in the description.

16 and 16 are lues through which combustion gases are drawn down fromvthe flue 6V11, underthe action of the injectors 17 and 17 respectively,and forced under the grate of the producer 2. A v

18 and 18 are the side walls of thepoven and 19 and 19the end-walls. v

20 is the fuel chute of producer 2, 21 the ash door giving accessto theash pit 21 and the grate 21 of the producer.

A22 are the hand holes having coversl 23 -which provide access to thegas nostrils 10 and dampers 14. v

24 and 25 are, respectively, the hand holes and covers of the airnostrils.

The air recuperator 3 comprises a series of 'fiues 26 connected two inparallel so that the gas current passing through them is divided betweentwo iues. The ues 26, in the form of recuperator shown, arch A27 within'the vertical lues 28, 28 and are spaced bythe spacers 29. .The ends ofthe iues 28, 28 are closed by the s ecial tiles 30 which are made toexactly fit 't e exterior sol ica

are built up from the of the Hues 26. There are thus formed two chambersinto which the ends of the Hues 26 open. Horizontal partitions 31 dividethe chamber thus left in the front of the oven into three sections, 32,33 and 34, which form the return connections for the Hues 26, dividingthem in effect into a return-bend Hue composed of two parallel sections.The horizontal partition 35 forms the return-connection 36 for the upperHues of the recuperator at the rear. VThe partition 37 forms thereturn-connections 38 and 39 at the rear of the recuperator. Connectingwith 38 is the passage 40, ythrough which the products of combustion,which have passed through the gas recuperator 4, enter the chamber 38and join the Hue gases which have passed through the upper part of theair recuperator, the combined currents passing thence through the lowertwo divisions of the Hues 26 of the air recuperator, and through 39 intothe Hue 41 leading to the main combustion gas Hue 5. A tile, 42, serves,as a damper to the passage 41. The air enters the recuperator throughthe inlet passage 43 and passes back through the Hue 44, whence itpasses through the ports 451, 45H, 45m, 45W, into the main air Hue 28.The air discharges from the Hues 28 through the ports 46 into the airHue 46, thence into the uptake-Hues 9 and 9 respectively, from which itpasses through the respective air nostrils, 11H, 11W, 11W, 13, 131V,-

13, into the respective'combustion Hues 6 and 7. V

The construction of the producer gas recuperator is similar in principleto that of the air recuperator. l-IIorizontal Hues 47 provide a path forthe passage of combustion gas through the recuperator. These Hues 47 arebuilt up from the producer arch 48 within the gas Hue 51, beingseparated by the spacers 49. Tiles 50 prevent communication between theforward ends of the Hues 47 and the producer gas Hue 51. The chamber 52forms a return-connection for'the Hues 47. The arch 53 forms the chamber54 establishing communication between the inlet ends of the Hues 47 kandthe lower combustion Hue 6V, A tile, 67, serves to regulate the HowV ofcombustion gas from the Hue 6vn to the upper set of Hues 47. Nostrils,561, 56, 56m, 561V, provide passage for the producer gas from producer 2to the gas Hue 51. A passage, 57 establishes communication between thegas Huey 66 and the gas up-take Hue 8. Hand holes 58, with covers 59,provide access to the Hues 47 of recuperator 4. Hand holes 60, withcovers 61, provide avmeans of access to the Hues 26.

The method of operation is as follows z-A bed of ignited fuel havingbeen built up in the gas producer 2, air is discharged under pressureinto the primary air Hues 62 through the nozzles 463. Nostrils, 64,establish communication between the Hue 62 and the ashi pit 21 of theproducer 2. Under the inducn tive action of the current of airdischarging from 63 into the throat of injector 17, combustion gas isdrawn down through the Hue 16 from the lowest combustion IHue 6V,mingles with the air from .nozzle 63, and the combined current ofcombustion gas and air passes through the Hue 62 and nostrils 64 intothe ash-pit 21 of the producer 2. Passing through the fuel bed 65 on thegrate 21, the oxygen and carbon dioXid of the draft current react withthe carbon of the fuel to form carbon monoXid according to the followingreactions, viz.:

The producer gas passes through the gas nostrils 561, 56H, 56m, 561Vinto the producer gas Hue 51 -of recuperator 4. During its passagethrough 51, the producer gas is heated by the sensible heat of the hotcombustion gases passing through the Hues 47. As l aim to operate myfuel bed at a comparatively low temperature, so as to avoid HuXing theash of the fuel, the producer gas leaves the fuel bed at a temperatureof from i600-18009 F. The combustion gases, on the other hand, dischargefrom the Hues 6"II at a relatively higher temperature-say 2200o F. Evenallowing for the necessity of a considerable temperature diHerentialbetween the combustion gas and producer gas, there is thus aconsiderable range of temperature-say, 'about l20G-300" F.- throughwhich it is practicable to raise the producer gas. The hot producer gasdischarges from the Hues 51 through the passages 66 and 57 into the Hues8, 8'., passes up through the Hues 8, 8, from which it passesthrough-'the several ports 10 and 12 in portions regulated by thedampers14 and 14 respectively, into the combustion Hues and 6I, 6m, and 6V, and71, 7m, and 7V, where it is burned. A portion of the hot products ofcombustion passing through the Hues 6"Il and 7VII is-diverted into theHues 47 of each producer as recuperator by opening the dampers 67 untilthe proper distribution of the combustion products between the tworecuperators has been obtained. The Hue gases heating the producer gasrecuperator pass through 54, 47 and the passage 40 and mingle with thestream of combustiongases from the upper Hues of the air recuperator inthe chamber 38, the combined streams passing through the lower Hues ofthe air recuperator and thence through the dampered passages 39 and 41to the main stack Hue 5. The relative proportions of the two Streams ofcombustion gases passing through the two recuperators should be soadjusted that both streams reach the chamber' 38 at approximately equal'temperatures.

, superheated producer The upper heating iiues 6I and 7I are heatedsolely by the sensible heat of the gas introduced through the ports 10and 12 respectively. This portion of gas passes along the lues 6I and''I to the other end of the oven. I-Iere an excess of air is added inquantity sufficient to not only burn all of the gas passing into thelues 6II and 71I from the flues 6I and 71, respectively, but also toburn about one-half of the gas which is added to the current at theinlet ends of the lues 6m and 7III through the gas ports 10III and 12m,respectively. The gaseous currents, now composed of combustion gases-andan excess of producer gas, sweep through the flues 6m and 7m to theother end of the oven where an excess of air is added to the gaseouscurrents through the air nostrils 1lIV and 131V.

The proportion of air which is entered here should again be thaiJ whichwill not only burn the excess of combustible in the currents enteringthe flues 61V and 71V, but also about one-half of the gas which is to`be admitted through the nostrils 10v and 12V, respectively. The burninggas sweeps through the flues 61V and 71V, and at the entrance to -theues 6V and 7V respectively, receives a fresh addition of gas through therespective nostrils 10V and 12V. The excess air entered through thenostrils 10W, 13W burns part of the gas entered through 10V and 12V, thegas currents sweeping through the iiues 6V and 7V and into the flues 6VIand 7W, respectively. At the entrance to 6VI and 7VI the gaseouscurrents receive their final portion of air through the nostrils 11W,13W, the air admitted here being limited to that required to secure theexcess necessary to complete combustion. The gaseous currents afterpassing through the ues 6VI and 'TVI should, in proper working, becomposed only of products of complete combustion, nitrogen and a smallexcess of air. In the lues 6V and 7V, respectively, the combustion gasesare divided, as before explained, part going to the producer gasrecuperators and part passing through the passages 22 to the airrecuperators.

In regulating the distribution of glas and air to the flues 6I, 6H,etc., and 71, I, etc., it is my aim to so regulate the proportions inthe several iues that an approximately uniform temperature is securedthroughout each series of flues. While I discharge the combustion gasesfrom the combustion or heating ues 6VII and 7V at a comparatively hightemperature (about 2000 to 2200 F.) I do not thereby withdraw the heatof these gases from the system, since, by using both the producer gasand air to recuperate the heat of the combustion gases I am using, inthe recuperators, currents of approximately balanced heat capacities.Therefore, I return to the combustion flues in the air and producer gasthe bulk of the sensible heat which is carried out of the iiues by thehot combustion gases discharging therefrom, the exact roportion returneddepending upon the e ciency of the recuperator used.

With a good efficiency in the recuperator, the gases discharged to thestack iue may be cooledto 200 to 300 F.

Having described my invention, what I claim is:

1. The method of conducting the combustion of gas, which comprises,instituting the combustion of a portion of said gask with a portion ofair, and prolonging the flame of the initial combustion, by addingthereto, alternately, a further portion of gas and a further portion ofair, the said further portions of gas and air being added at suchintervals as to maintain the initial flame substantially continuous.

2. The method of conducting the combustion of gas whichcomprises,instituting the combustion of a portion of said gas with aportion of air in excess of that required to supply oxygen for thecomplete combustion of said portion of gas, and prolonging the flame ofthe initial combustion by a secondary combustion caused by addingthereto a further portion of gas in excess of the free air remaining inthe flame gases from the initial combustion, followed by a furtherportion of air in excess of the unconsumed gas remaining in the iamegases from the secondary combustion. l

3. The method of conducting the combustion of gas to secure a prolongediame, which comprises, instituting the combustion of a portion of saidgas with a portion of air in excess of that required to supply oxygenfor the complete combustion of said portion of gas, and prolonging theame of the initial combustion by a secondary combustion maintained byadding to the flame gases a further portion of gas in excess of the'freeair remaining in the said flame gases from the initial combustion,followed by a further portion of air in excess of the unconsumed gasremaining in the llame gases from the secondary combustion, andrepeating the additions of gas and air, in like manner, until thedesired prolongation of flame has been secured.

4. The method of conducting the combustion of gas, which comprises,burning a portion of said gas with a portion of air in excess of thatrequired to supply oxygen for the complete combustion of said portion ofgas, and adding to the so-formed hot gases a further portion of gas,followed by a further portion of air, each of said portions of gas andair added being of sufiicient quantity to establish a momentary excessof gas or air, as the case may be, in the gas mixture.

5.` The method of conducting the combustion of gas to secure a prolongedflame of approximately uniform temperature which consists in burning aportion of the gas with an excess of air and then separately adding tothe products of such combustion a further portion o gas followed by afurther portion of air, and repeating said operatioiis, the volumes ofthe respective portions of gas and air being regulated to-that requiredto maintain the temperature of the stream of gases at, approximately,the temperature of the products of the initial combustion.

6. The method of conducting the combustion of gas, which comprises,preheating said gas, burning a portion of the preheated gas with anexcess of air and separately adding to the resulting hot gases, anexcess of preheated gas followed by an excess of air.

7.. The method of conducting the combustion of gas which comprisespreheating said gas and preheating air, burning a portion of thepreheated gas with a quantity of preheated air in excess of thatrequired for the complete combustion of said portion of gas, and thenadding to the so-formed mixture of hot gases additional portions ofpreheated gas and additional portions of preheated air, each addition ofa portion of gas being followed by the addition of a portion of air,each of said portions of preheated gas and air added being of sufficientquantity to establish a momentary excess of gas or air, as the case maybe, in the gas mixture.

8. The method of conducting the combustion of gas to secure a prolongedflame of approximately uniform temperature, which comprises, preheatingsaid gas and preheating air by heat abstracted from the gaseous productsof the vcombustion of said gas, burning a portionof said preheated gaswith a quantity of said preheated air in excess of that required for thecomplete combustion of said gas to establish an initial combustion, andthen adding to the products of the inigrease? tial combustion aplurality of separate por.. tions of preheated gas and preheatedair, theadditions of said portions of preheated gas being alternated with theadditions of said portions of preheated air, the volumes of therespective portions of preheated gas and preheated air being regulatedto that required to maintain the temperature of the stream of flamegases at approximately the temperature of the products of the initialcombustion.

9. The method of conducting the combustion of gas to secure a prolongedflame oi: approximately uniform temperature, which comprises preheatingsaid gas, and preheating the volume of air required for the cornbustionof said gas, introducing a portion of the preheated gas into arelatively long combustion flue, introducing a portion of the preheatedair in excess of that required to burn said portion of gas into saidflue, whereby an initial combustion is established in said iiue, addingto the gases of theinitial combustion at an intermediate locality insaid flue, a further portion of gas in excess, following this additionof gas by adding a further portion of air in excess, at a localityfurther advanced along said flue, and repeating such additions of gasand air at regular intervals along said flue, the volumes oi therespective portions of preheated gas and preheated air being regulatedto that required to maintain the temperature of the stream of flue gasesat approximately the temperature of the produc'ts of the initialcombustion.

Signed at New York city, in the county of New York and State of NewYork, this 16th day of January, A. D. 1911.

HENRY L. DOHERTY.

Witnesses el'. M. MCMILLIN,

FRANK L. BLACKBURN.

